Interactions of the elastctic subsoil,piles,strip foundation,three layers and multispan structure are studied by engineering approximate method in this paper,semi-analytic solutions for the issue are obtained.

By the project example,this paper makes full use of mechanics principle,analyzes the trait that reinforced pressure zone can be disconnected and reinforced by pulling through,and puts forward the design points of under column preformed hole reinforced concrete strip foundation to provide ideas to engineers and technicians.